I just registered, so I could ask this question. I would like to know if it is possible to create custom speed presets, and if so how. I am rather confused with the units used to determine speed when it starts to get to ' c '. I can understand 100,000 kilometers per second, but what is " 0.30 c " ? What is that speed in kilometers?

I'm asking this because I would like to have a "Speed of Light" preset which would literally be 300,000 kilometers per second, or at least the equivalent of it in " c ".